Teddy tries to convince Bob and Linda to donate blood with him at a vampire-themed blood mobile.
Two years ago, a house runs out of candy for Louise, but the couple promises to give her double the candy the following year.
One year ago, the couple forgets about their previous agreement and they don't give Louise any candy because of her rudeness in demanding twice the amount of candy.
Louise plans on stealing the entire bowl of candy from the couple this year to get back at them with the help of Tina and Gene.
Someone from a local hotel calls in a delivery order at the restaurant and Tina suggests that her, Louise, and Gene deliver it to stall Louise's plan.
The kids take the order up to room 313 in the hotel and find a woman performing what looks to be a seance.
They run out as fast as they can, but Gene leaves the snail shell part of their costume in the hotel room. They have to go back to get it because it'll help disguise them when they steal the couple's bowl of candy.
The hotel manager at the front desk of the hotel tells the kids that the woman they saw was Dolores and that she was conjuring up the spirit of her dead lover.
Gus approaches them in the lobby and tell them that Dolores' lover died on Halloween night fifty years ago in room 313.
The kids go up to the room and get their snail shell. Dolores tells them that cheeseburgers were her lover's favorite food so she is using it as bait to lure him, Roger, there and banish him to Hell.
The kids decide to stay.
Teddy takes Bob and Linda to the blood mobile and Bob is convinced to give blood.
Dolores tells the kids the story of the night Roger died. They had attended a Halloween party at the hotel, but he sneaked off with another girl. She left devastated and found out the next day that he died of cardiac arrest.
Tina makes a deal with Louise -- if Tina can prove that Roger wasn't a cheater, then Louise won't steal the couple's bowl of candy.
Bob pulls out the needle from his arm and passes out.
Tina figures out that Roger was allergic to the peanuts he was eating that night and that the girl that he snuck off with was actually a male doctor. The doctor took him up to his room after Roger was feeling ill.
The phlebotomists find Bob laying on the floor unconscious and help him.
Louise agrees to not go through with her plan.